Load thumbnail instead of lowest resolution

Lowest resolution retrieval then scaling is too expensive for
very large image. Load the existing thumbnail instead.
Remove commented out code.
Fix #10602 and clean up IO code.
Retry when a lock exception occurred. (see #10604)

When running the server locally and using 4 re.
lock exceptions can occur while rendering an image, retry.
Close session of all found OMERO clients in unloadOmero()
Fix max retry to 2.
Do not reactivate RE when reconnecting if not active.
No longer handle null result.

This is no longer required, the image is now updated
using the update method.
Remove commented out code.
Remove method w/o implementation.
Review shut down sequence (see #10633)
Fix left shift (see #10595)
Merge pull request #960 from will-moore/split_view_10094

Split view 10094
Merge pull request #959 from will-moore/web-bugs-March25th

Web bugs march25th
Add typeinfo header for bad_cast definition
Assert perms using perm->is*, as can* only works post serialization
merge dev_4_4 -D org -I include -E exclude: PR 821 (Connection)
merge dev_4_4 -D org -I include -E exclude: PR 949 (loadOmero() improvements)
merge dev_4_4 -D org -I include -E exclude: PR 953 (Update dev_4_4 submodules)
merge dev_4_4 -D org -I include -E exclude: PR 963 (Add more C++ tests)